Anatomy
Physiology
CCS
PPH/PATH
MISC
100
What spinal roots make up the brachial plexus?
C5, C6, C7, C8, T1
100
What is a motor unit?
A single motor nerve and all the fibres it supplies.
100
What is muscle tone?
Muscle tone refers to the amount of tension or resistance to movement in a muscle.
100
Which age group is most likely to engage in risky alcohol consumption?
18-24 year olds
100
What do type II alveolar cells secrete, and what is the physiological importance of this secretion?
Surfactant: lowers surface tension to prevent alveolar collapse
200
The spinal cord is a continuation of what brainstem structure?
The medulla oblongata
200
During synaptic transmission, what ion triggers exocytosis of synaptic vesicle contents upon entry into the cell?
Calcium
200
What is Phalen’s manoeuvre?
Holding the wrist in flexion for 60 seconds to elicit numbness/pain in the median nerve distribution
200
What is Wallarian Degeneration?
Degeneration of the distal segment of the axon after an axon is severed, crushed or damaged
200
What is the rate limiting enzyme of glycolysis?What are the reactants and products?
Phosphofructokinase-1:
fructose-6-phosphate + ATP -> fructose-1,6-bisphosphate + ADP
300
Where is a lumbar puncture inserted, and under what circumstance should the procedure not be performed?
A lumbar puncture is performed between spinous processes of L3 and L4 (or L4 and L5) vertebrae. A lumbar puncture should not be performed in the presence of increased intracranial pressure.
300
List 3 key features of rapid eye movement (REM) sleep
Any 3 of:
Occurs 90 minutes after sleep begins
Darting of the eyes
BP and HR increases
Skeletal muscle paralysis
brain shifts to a highly active state
dreams occur at this stage
300
Compare and contrast the features of lower vs upper motor neuron injuries.
Lower motor nerve features:
weakness
Wasting
Hypotonia
Hyporeflexia
Fasciculations
Upper motor nerve features:
weakness
hypertonia
hyperreflexia
300
List 5 facial features of a child with fetal alcohol syndrome.
Any 5 of:
Small head
Flat midface
Underdeveloped jaw
Low nasal bridge
small eye openings
Epicanthal folds
Thin upper lip
short nose
300
What are the borders of Hesselbach’s triangle?
Medial: Rectus abdominis
Lateral: inferior epigastric vessels
Inferior: inguinal ligament
400
Which part of the brachial plexus and associated spinal roots are affected in Erb’s palsy, and what are the 3 common mechanisms of injury?
Injury to the upper trunk of the brachial plexus, involving the C5-C6 roots. The 3 common mechanisms are:
Birth injury → excessive pulling on the baby’s head/neck during delivery
Fall on the shoulder
Blow to the head/shoulder causing excessive separation of the head and shoulder
400
Describe the three mechanisms of neurotransmitter termination.
1) neurotransmitters can be returned/recycled to axon terminals for reuse or transported into glial cells
2) enzymes inactive neurotransmitters
3) neurotransmitters can diffuse out of the synaptic cleft
400
List 2 features of ulnar nerve palsy
Loss of ring/little finger flexors (FDS/FDP spared in distal lesion) and abduction/adduction
Numb hypothenar eminence
'Claw hand' with extended ring/little fingers at MCP
Interossei wasting
400
What is primary prevention in the context of alcohol consumption? Provide an example of a primary intervention.
Reducing the incidence or prevalence of alcohol misuse and problems related to drinking behaviours.
Examples:
education campaigns to raise awareness of the consequences of risky alcohol consumption
Alcohol taxation
Legal age of drinking
Random breath testing
400
A patient presents with a left-sided hemisection of the spinal cord. Which neurological deficits would occur ipsilaterally, and which would occur contralaterally to the lesion?
Ipsalateral: motor paralysis, sensory (fine touch, vibration, proprioception)
Contralateral: sensory (pain and temperature)
500
List the five terminal branches of the brachial plexus and state the spinal nerve roots that contribute to each branch.
Musculocutaneous → C5 - C7
Median → C5 - T1
Ulnar → C8 - T1
Radial → C5 - T1
Axillary → C5 - C6
500
Provide the step by step mechanism of how a muscle contraction is initiated, starting from the neuromuscular junction and ending with actin-myosin binding (the steps of the contraction cycle don’t need to be explained)
1) somatic motor neuron releases ACh at the neuromuscular junction that bind to nicotinic ACh receptors
2) Na+ entry into nicotinic acetylcholine receptors causing a muscle action potential
3) The action potential travels into t-tubules and alters the conformation of DHP receptor
4) The DHP receptor opens RyR channels on the sarcoplasmic reticulum → causes calcium to enter the cytoplasm
5) calcium binds to troponin allowing actin-myosin binding → muscle contraction initiated
500
A patient has sustained trauma to the posterior triangle of the neck. On examination, the medial border and inferior angle of the scapula are unusually prominent. Which nerve is most likely injured, what are the spinal roots of the injured nerve, which muscle has been affected and what is the muscle’s functional deficit?
The long thoracic nerve (C5–C7) is injured, resulting in weakness/paralysis of the serratus anterior and producing a winged scapula. The functional deficit of the serratus anterior would be difficulty/inability to do shoulder abduction above 90 degrees.
500
Describe the process of peripheral nerve regeneration following axonal injury.
1) The basement membrane remains intact and the distal portion of the injured axon degenerates
2) The surrounding myelin sheath breaks down around the proximal axonal tip
3) Macrophages then clear away the cellular and myelin debris.
4) Axonal sprouts begin to grow from the surviving proximal stump at approximately 1–4 mm per day.
5) Schwann cells and the intact basement membrane help guide the regenerating axon along its original pathway.
6) The Schwann cell membrane then ensheaths the new axonal sprout, restoring the myelin sheath and helping to re-establish nerve conductivity.
500
During the initial contact phase of the gait cycle, which three muscles/muscle groups are primarily involved?
Initial contact:
1) Hip extensors: contract to stabilize the hip
2) Quadriceps: contracts eccentrically (muscle lengthens while under tension)
3) Tibialis Anterior: contracts eccentrically